SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b10b6f3a198a03d15ed25ab0263923d0baaf588241d8c38c656e03d64d6c37c' 
  AND token = '4lpze7Z0gx4M1B9OCuEKvgAOuVJkW+V9+Xx/0wVq09w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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