SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6aca0a4978543c396b8ca4c6d8d7f2a8d54cc9660da6d949426ffc4d97f34c91' 
  AND token = 'b5vMtgSstOx80n/oEwOypXpDTt6kWT4nYYv3WPtmOR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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