SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c40e6bd272a671e2febf8713facfb21fcf7a522763ccfad7980feb130fcc7ec' 
  AND token = 'YeE7XCu6UqoaWsaFFGZcLWkQPuddCpx/A41lx+L0WJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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