SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5700ca476489127c9431e20372856d9eb62255129dc1f66b71096d66a5ad1e13' 
  AND token = 'mRrRrzUOqm4qwo07jQ509uZL8IagJXA1x4d+vIFgMiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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