SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21159127ba198f98051a993c191db35727328863b02ed774b78d027a0d636e30' 
  AND token = 'jnx6C0l+g7vJ/8PYRCXpuPa/WZBC7eQGFsMQxqqA5XM=' 
  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"
    }
  }
}