SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1607db19eac25e1ea5f929433ccc7cf644e70599da5b63196496049fec2bb7b1' 
  AND token = 'HXjrGhOVqfYRlIqh5Opcbxgzjd78rLpQc1nJsHayJ3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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