SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0269240b0a996ab583438e259fc79e9b21ebbe938341b7c2526ee52aadbf3a44' 
  AND token = 'X7zg1FZHUcneiZ5Ht9pzIQ/1dgBHyxCoI7FaYUOyO4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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