SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ba8f60a0fad23e06b05c977bdb6249d0c0a9be6cc720963684fcc0aecc6621fe' 
  AND token = 'wjD7A++aG7ok1Et2AikJhp78smdnQn674vEVnzGzW7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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