SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c94158a68f7f5a720a19c3bf56b524f920af8538a6a478978e5dbdba6cb81bc' 
  AND token = '+4qZexq0OaDWw6tV2aJJK++HX8BQWM/Xor7jpuDL5P8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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