SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f4a93d2369a9fd8ad1d9de52d09e6cdca0fae430cb177eb70610d59cf36d51' 
  AND token = 'pht3KP2JauRh9rH+i66d51zZ/OqQKoFEmCaGRdXO0P8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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