SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4280e9d93d5751bc32a30e093333fb3158d20ae2cbcac9ac08789878b8254af' 
  AND token = 'H3SzWb/CzNKjnuP8P6+GFYQ/fJWBz/tu+1ZCzhrvRTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}