SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5acb1ca592b1303be7e1f516b4d1bbeec7c9ebd4a38aef3494c02f6848d15b84' 
  AND token = 'qUCGFxgA6ZWsp8nxaerDVcSbsSRPSKxgZBMxYEjAbm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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