SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c13c350d511c7dc7babbc28db46b9a9e245641aea49e9807a1971ea891a07ef' 
  AND token = 'biyCvym8T4WU4Yfin6TpsYUktlmGDUUpwjle9gH0kpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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