SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30920c5e25d3e5ebdc9f94f9c2618c1f23696ade0e18e73327525e4467be99d' 
  AND token = 'FFDjGyCgNpILochh9jhe3x5J8whyYQZzFbeGA/z/qE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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