SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c28e86f4a855fba55486a690c8c62fb460c5cb30a0aadfc70dcfd81a3dff13' 
  AND token = 'kUJio5eZXuBmYGvxRJBRpwrzNm5+pU7gPg0qnKFhMWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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