SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7c674eff912ce2f433a656965c87fa6015bb4bbba17459a385c5978161985dd' 
  AND token = 'MGLuzCeJ1fZqpnZ/Pr61SwJybaBZiNdaJt/NLXjnRNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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