SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aa727cb04b541e62be0ef31763c5401b21cf8c0fd08c8e252658d6ef8097028' 
  AND token = '8WqbXPJYh7Xc/pkbjXqDWovSawBlVjbyICMJzxqJ9QI=' 
  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"
    }
  }
}