SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '416bcc1964243973635aaddc03bca8ee2fd28b99c7b32d7cb6fd38d8be2a926c' 
  AND token = 'IXVY0GpnsiScdtNy4273MqDfjxsTELXd7kwsy+PkAgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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