SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f4ea217f03e4539e55eddaf3f7c6e75a80f17b656162a696c230a0486aab96' 
  AND token = 'DNKVsITmih0FFOJ3PLN2UaTxNP5ZJv7ugjqLJdDT4S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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