SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48d759518112a0b25847519f78859827ca900d01895485da4d3a5ec1ece21227' 
  AND token = 'jk3zfXUY7U/FV+BlnMbSBa6izSd1WoJBiB3K4ObrfmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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