SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bed3d4c98178864b4f10b05c4ce11324edc0c7668d7b552921e0abd6873b7c2e' 
  AND token = 'hKMiZEs0MFdwWRin0c7hEnrad9OdnhTMeclkfVVdbqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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