SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c69ed7c51c71c18588dd9a150a998493bf962d92ea1de86e1cfeaa5b511fd6e' 
  AND token = 'R7zHiP46vk3a+Mb04fpnz+5ztDYxKjBlT9Jeoytd7Gc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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