SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba87c0992295a48250249cc8ab57bc1bc2083c706e47fd5d823b810a56b0ae58' 
  AND token = 'xx/QSqt1qRww/sgrYBvvZqhurBlfok0qKvh4YZjEUtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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