SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be2c2ae8916638fa7188f7901a238d69c5be9b9ff7acfdd348405e3798f7672b' 
  AND token = 'HFtHFTtCqIcfXWpDQ0SGFC0ERX1vQuRN/SDZ5XT2uI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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