SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b263fed1e4c7ba4ca4730f3bfabc77d9f145eb28cd632ac69aeb1e59119449c' 
  AND token = 'KD9Ye+IEy/mtajSUMD8hXDWcssVN9VDaBqPIXO4vab8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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