SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde562b34d65749bfde6a6ec542f20e813e6547decc95f1ce4ce36c026b2da9e' 
  AND token = 'dUkqXzLOeR6T9FXFQPP7N2V2mKBvtiJwifhL3vZNaWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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