SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dacfbed69e50584ae6f7b0ffa75859336be063359a9c87eb2e38ccbf6d1b4a4c' 
  AND token = 'jVIplsL565ks3BWqoE1BkYwAsqmpchVzGrKMx4wMJn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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