SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98fa09c829703dcfc3dc02e812ebf4c4e2c5238412756fb3936626e968371288' 
  AND token = 'buTzSSndurHKbvFzZGpHwnZ180WQjInV7o0QfJQEDMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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