SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa2921ac8677de4253d3fba657033de6755549a2cefb07b9e7623d7c2b98f823' 
  AND token = 'lA6qNm6Kc7IIuZAQ3QFQUKB0Z1gSs67Tk/bjGR8ZPGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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