SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c0532beb2409a126debd0739dd32bfa0cf6d6bf5e91e59d8d96e4b99d1301bb' 
  AND token = 'rgVrrTLZ8CdLDLK81U4oCMClFlwyaPvMhmB44WdGw7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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