SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '849c15a8e67a710f25c21e64a79f13c0a752e11d30e3d94d7eb51ce7ffa29be6' 
  AND token = 'jMv/bhG94e7Sas+/BH/Gi8YTgCfB2FqNLvu//QByGjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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