SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b512175ef155a9bc2259f5915515fe6d478fc20fc51c2824710e55395f9e37d' 
  AND token = 'ijf1U1H88pZrY5e1moldXQVHVXhsdGpVcA0ZP5+lA08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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