SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c82e82ece7a167555e3a1f425fa6b6af3e170caa203a3303eef25cbfe43ded0' 
  AND token = 'x7VZQriVg2Z1NhmnGW8LD1JAHbqD2C3MBbNIh68ubQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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