SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67a80b74862651ba7bd5d34ff09a3a9fa64c5219c0ae1890226b6f86b4fdef98' 
  AND token = '6baVTICbMa+lZ28GakFBwAABhxt4G/mpPCXrq/Z8GYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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