SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcd424a53394408dded4d02db06789aa53300ff7f76ab84d021025d848fb87b9' 
  AND token = 'WFOwtjx5NAOOmOMFR0xQ1aodgmk+90oGxZf2dxiL798=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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