SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6da24c1e44fc2629f81eec1c7b09769ec1903123667932ff432d6f4b0556b2f8' 
  AND token = '7m6dtJ1OT+J0EnoRRIAr1H3meQgNVALGv3hBvp1zO10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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