SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe0d94d217a220be6b3d9ddc7a3b358cc93020786c12f65c94f08731c63ff0a' 
  AND token = 'hMBeCdqhqv8wVAgs/nlb2ks/RbAwcxe3ljrjt3VoSR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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