SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7f496c1d65e5e0a5eaea3ba90da2a26ebf301c9c8bd0684e11845806cfe854d' 
  AND token = 'ertJ17YikLKtSAlssKod+Ir5/hMWvwmxgrGCXR0Adsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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