SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d7fc7832e2341f413336c202b79c3b071f05acb4627fa8fffd9e76f2ea4ccd' 
  AND token = 'RVHdymWG5W3JZ1kilA1GU+QLK1fnGI8o5JENXRbZklw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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