SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f33d0abc93a61feb2619b0023527093d55ed5cdcc8b2515edd18c9caca627f6' 
  AND token = '/HK5oHLaAoJ4PwuJsRLahz6exwsVZITWINcuC96M7eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}