SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79234827d853a209ac6d332c47b52e7a0b2aae45b1c31533f5188eb775059915' 
  AND token = 'TKKDJ7MOG7UgZh5cdsUfCzpzZy3PiK2LKOi4FKk8M90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}