SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2106bb9680cd62e2087fb258f352b3d883875b4de2cf4c20c912d05dcd29f8fb' 
  AND token = 'PK4TMH8pT5QjjW5HuDBdiPzLxG6KSOXkAzBYyu+wgCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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