SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9e15195c006eea4af58a5da806ee42c37677596f28646a3085f18e11fef4884' 
  AND token = 'Mp+/Woj0WZoZlFMgQbYZQ9fOvWGjMPSJ2ld7NpOft4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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