SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3416e011c3e767ae94facd5d57f9b0611c2166c87022c083bc390b35a53a638b' 
  AND token = 'vj13GcCJiMPUaszyL4KhdJhWKUR6g2e1HszBbZ5Gj2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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