SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3054e320b773189a14962dd1eb2833c1176969184ad1e0dca0031abed8f06743' 
  AND token = '1e3TWydE+IVURO+5PGmMLnTT4YFtIzCaxDiTFIMy/sM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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