SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3f547ef624e02b7acc3614291f1730cc13b05fb60b28c190f37916cbd273b84' 
  AND token = 'Pw9T2+WMFg56/UT74nNS2rp5Yh3MaBrHujuiGDexgcI=' 
  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"
    }
  }
}