SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ce7747e0ff2882fa6771fdae20f5befa791d97fbd708478833c57a67da9424' 
  AND token = 'jC1DsBpSrbxQtgFzm0u4gKD8ZDZeCzq0gF4WoDVAwRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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