SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '029a9070d91e840bd8be686974c931c0485dc66d3d93216f2f280ae0e80b99b8' 
  AND token = 'OdY6eRBElp1fBb0iaCXfRuymunKp6wXrCsVMv+ibnmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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