SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d12d993e0c1ba52a9b2bd345ea874bf9a5e8add7d8b13fdcd6a6fa059675ac9' 
  AND token = 'xQ5h5guHUTgTYB+lEmiAcGgrU8Y/GbM0VSNq8Rrzwro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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