SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5578b29c8a341d24617ddc91bb5ccf5347c25f7287a1ef8fbba114f6975cda29' 
  AND token = 'I85+ryPFGyBkKHjJ8RNRpZDCOPSHxtNZI/eLfwBCgB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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