SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '203feae48181edabe609c9ea485982325c7dfcd783c8491b6dac99d746fbb0c5' 
  AND token = 'fGRoG0lXmP0um5autddG3qQNQsJxe1EXvQBPlLVKHVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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