SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fdaad93429be1919934c7d802f3f01266890783551fee4c5455cf82f433e837' 
  AND token = 'k7kNmJ0eXq500WgzyEtHCSga7ZuwZ84Q77M7UNuZ7Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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