SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9891ba99c23ac0ef874383caf5db34b5ae8e1b26ae5e5df6f0fcc7331bbd8649' 
  AND token = '4+JFslMhj8vorWSFLD+MANtC3VzJsnEMTDutvRCdmVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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