SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab5f5764da756a6a97e5224639457d762534033933635c97f7553993b9f7eaa' 
  AND token = 'GYWhR5VYdJCFw/LdjxXqWbBFO6VFAb39SXGfknI1T8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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