SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91b03b61dcae5518f8d83dfd982f3ef38fd134e65f3782b52d0ac40fcc7c3273' 
  AND token = 'VCDUFakEeiaIBVD+hHUSLyyAupXypmr7fOU3PNv7DTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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