SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e157fa5592ef66fc5e2df264e95678f95667e5b706d4dd0ad90a72a7de70a26e' 
  AND token = 'ulcL6a0h85QIGLd5yvG9g3a7KM+EL1TPAEXSn6xXvCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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