SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a34b82fe66baf967ba68f6802a73d4a93d3f5d49f31779e364bdec8c0a69c9b9' 
  AND token = 'EGYjSDCmuqgt7+9edS+HyWIzkR8UCBTPzaHwugLHWzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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