SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff390b41f78417318d22d8767a6ac4d89c41da36b4a466bb65356e71cbe4f988' 
  AND token = 'TAE4qaNeJ8t9DfQIf16We+j+dcy0AaSw3alM7DIXrZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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