SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c946108ed4fc82b627ba33bfde5583d48b608b44db0e6fe70407609339b865b' 
  AND token = 'UBNdvp6fUlekTToYHyCFF0E6f6CW3nTgqH/m60dQ1tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}