SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '08760826f132e1f4a566f96fa819bf3577ea527c2f9bc854c4c23aaba6a69074' 
  AND token = 'oBqQFpCS+Lo9AgdVjCwMZUFaO8rigxaRmsufOkOixSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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