SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '62bcaa9f7078960a2c438bc90f344647131f4bfc43c70e2a2b56ddd5b9508339' 
  AND token = 'qUSX4LCegsWi+uLlxDlQmptlkcF0pJ55FJ3nIPddm1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}