SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5eae99156405ab20e1e6bc62a007f3f318da280c78ca3ab2b4c38f77dc737423' 
  AND token = 'FewbOo516PVGh4Vg1muY6HJK7CCcPwdYYNTTDuJT+44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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