SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3714068b89ffcb839b280a9fb167ebbe767f271690654fb5f443d17827817b5' 
  AND token = 'ecAnWgJZhwQauPdsJYwTaxxWKvP+ufJZFvSrBq2bRcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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