SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1a5382ddc465419e0497453784ec7bb642d7962898ddeb26dec4cd3ddcf5b6' 
  AND token = 'v1b8KSfOik8yTXykxwoOGuRpdJyZUUEZCdYY4aROFTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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