SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589efaf4debe432bfddb51eca32c03f3f2217e2ea5e3692546f8eaba212763ed' 
  AND token = 'DJUUlbIVDxA0uVMf4pB03zMAVz43arv+FNaR59ET8Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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