SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a3dc3aaa72a6535e4588805b929d1d94d00d69a3c27621c0876a38590f81926' 
  AND token = 'yqyt5MUFxCHyaJXH3lzfCMn6ln+G+BwvC+chQzqZoi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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