SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b72cdc60e8bf115e9b20f0691bd0d737a6ac4c8501af8f06a8f3c02888bb23' 
  AND token = '69FpS65/Kzr1x4BarfZi/zVsSgRtypziNGs/VEwQJho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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