SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad72343f54f8a8455a81752addedc71c8d53fd3c03e0aabd6526ac92bf006d5' 
  AND token = 'c626X+LDknumkLvrT026qyL0eiuH1hNawZoLNA50fcI=' 
  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"
    }
  }
}