SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '763c330be840ad6115a2cc967483e54b651219f0f3140aa2f801170c2b9e0174' 
  AND token = 'ftVkHpYCjsEu4zK5EABrjKs4XyippR2v9IqNY6izFUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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