SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d1ceaee267251427244f51fb15ad63c31cc5a4afa0426850a4033f16ebbb3ff' 
  AND token = '23PM0IONZXYBu0TsDDN8LuwLNGJGIA2W6VsjkmyOTXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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