SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa432cc4e9437623984919ecf63c7ce27660198aecb80042347c142299e18dd6' 
  AND token = 'dPACprQuakzOmNqN3VQr3mkgUxQJo9S8HjA78kZ5Ak0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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