SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe2f2748d63d94efff68d299d49cd84b4e62b5e66adc525182f877ce7ea4b03d' 
  AND token = 'YwYq/P929F6n/nExui3nyrTHFIdiEB7QWbVVcH6WatI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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