SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe38e94b7edd553124f9072a2234284f84516c076037afdb5421dd48ad001433' 
  AND token = 'mtV2n7jXltkYU7z7L8gX8m0zAyMcgSrF/KxqjkwIyLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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