SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19670a7aca915e9172cda6bf7d739be30cab22454c043576d438bdd2d52b9fef' 
  AND token = 'heGFveIGOJvl0v1WJWQyByVA+vBs2U2rLCJfo/rDEg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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