SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ff54e5295986815945ca648d9830ed11135a9511fa967e3e61a170141cdd31c' 
  AND token = 'CIrWoCohwOoLZ512QltSnyaf+3okyWebEDZJwUMMNjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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