SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62d4cd1963dbf6204c508e12802018ef8932c1f727cfa9bf4f3467ea486df586' 
  AND token = 'QbobGRHJqmyYzDS3t762/ILZr2sOWuQovGa3f32UwqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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