SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5894dd3172094620c8d48f9507ae90f00fd147b5295a6cb00dcc20675d66631' 
  AND token = 'WpDw5qc++fs1jngZ5SwppsuPdKL2BmG26gbqlfJBvLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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