SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '591114802d484a77077b4be5fb0f3c56762e04681a266e46ce3cd99d42d9309b' 
  AND token = 'sOwXHrO0CgDK3AmeIBg1tdO+YIP0IWKpPwYN73dp1Cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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