SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aec52239558cf52da303aba2abb1b55d9c75fcdb5b787aae546ad767680f4d96' 
  AND token = 'OUsZ9GhgewoNwkejzMAQfm2GVoY39zxbUYssNqJ8IZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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