SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf886c567526a01662b700fde46402c3d2724adc98efcacd0b350131fec9501' 
  AND token = 'T17fReGxqMDqPjQodLWeS5Zm1KOk5xP9KbyFDiBMhEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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