SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9ef3759cb9432b3330e666eb98c3128b9683117a56c0242d20c2d01ad4e25cb8' 
  AND token = 'XwkeWoW/BoIT6dUxpRK5BTx+sy2qjV2cBJTVdT5uO0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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