SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eb0201988d67032c4f885797ec9aa84f902196ccbb3b1b8f8e4efbf0b4103bc' 
  AND token = 'PrGhTWtzA+DP+gfuYhea5tFcMs9qBUVzrNUQVICKJJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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