SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32578fb21d5d37abc2a0b4ac6ac7faba43443badde0958d5582fec9c476d42d6' 
  AND token = 'I/jrWO/9JuMYexM8YnPDbRmoBs0vl8d14KWwk/WHfHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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