SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dec0179398e85347aceddab7229e0aa62f217ab6b5e576bad2972689c2cc6c26' 
  AND token = 'mpligvC1G1k4fxcWiBfCZE3FfKTZQvsFBnqmOC7/bx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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