SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b835bb57bcb489ce5cbc629b8178adea5d38cfc1240bdf9a4e56604b14a4fbfd' 
  AND token = 'fYTlBw9P5111gfoS9TMPRv4xcxsI/LwVPgYv1sUqHK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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