SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85d48dcecac09e1b9f833658aa63e960c9687edc5246c1121ae14fdada8a4c48' 
  AND token = 'dpH1YR4yF5SKJOLKDSUcHPq7+y0f82Jef/lIHG2MiiQ=' 
  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"
    }
  }
}