SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '448e18be4df3c705f735a5aec0346ef2216bb78d06338d1feeea46bc048280ad' 
  AND token = '3a3RaCBMuCYkV6sMPDozpjBu49Z94wf62nq8538YtII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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