SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e78fc356eb38e09e922f38d17dbdc10956624217cc3486f03ae39382f14957d' 
  AND token = 'BlHSWBLXq37dZJmqmphvGCYCQOqKmIflwRbD1ATt00E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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