SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4625ca53555baa98056743f844a6d529400104738695bb5988a403113657f574' 
  AND token = 'EA/qYP0GqKZhgyqwGD0aGmFIGuPsG8k2rvGX8+GUp1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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