SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67172473c81ebde090328592eea57ad2beaf38a65f6032eac14f7025ebb5985c' 
  AND token = 'bPLG1HeJ2wGA2nxuQ+EkklCA0TEKgZavvMLnyYZmKtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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