SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59437e4676fa7846373bd12a6b2ec08969f02a9701425fa22c11f5100f0bc024' 
  AND token = 'zt0yqyLrpEzMtY3VN4/haqrLsx6/1+k5XarzCg6MSus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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