SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7de1e23b70ddd706af68284097cfff68a5dcaad4d64d3494961832d867c46c53' 
  AND token = 'FSJx1YJ/mqFmjbofGs4AU1thw1si1czYveQgZU3JfdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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