SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11961981f804c6d3dce33c643c9111ab61c3c52418023da925ac5c8f39881a6b' 
  AND token = '70NzOzpXZiNBnLVlKEGMS5lHT/AhTRDJH4rKPW5NgG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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