SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce5c182d1c38fbc5b7ca77dbdc1ecfbbab6d9bb408872844e3236a78251b3d2d' 
  AND token = 'IDTsgZMoW9NVtd56Nlea5WlBNkYDBkZrg/x3YSciZ60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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