SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d6c3c702654a4a2a3a4a990ebdc8c834a89e47e93c96b2b44320b29f1afeac1' 
  AND token = 'qp/dQ8eDqfKp3bhlmHpkSE74CSNWPjqwAISekPbvfdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}