SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '903a92d73818191fc2fa087d0ca86d3d47709f79bf7c52460a6c3de2f6cfa253' 
  AND token = 'h/rw+nzfu0aPaQqezt0PwcPo6ByOP/tvSeVGADBOoCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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