SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1f5a4b945e7f309e87139f279513bfec17f4d3bead6b0102f7a0d2fe1af491f' 
  AND token = 'DMPG/dCHie5R8NC8YeOMgOcZEmwJ7pwQO69MHkNvTYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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