Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7b0a795e91c36305118e99333e66aeef09271c76e52c38d3e354b24791ca5c' 
  AND token = 'lk+UiFZV2Iraus6NfZvorxYnVkHmK9Wa6IgjCWAVVDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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