SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39b15a19fe66214756b699eddd19b9256292125c7ce00df820847fad75897691' 
  AND token = 'jzTkcq+/zltNSKv1O3HltxBvDibYjZfSFTmfQ8llJvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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