SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '334e8de20144c6ff1a4fd43de8b228a0b74b0e160f3faa3428b041a9927581cf' 
  AND token = 'AiaiBPd82lvIoqbNMDyBQTDcs939gbrV+ncIBrnrKIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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