SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1da2a90ce8f4f507be788d005d285bd2237f48b136da806dbbb3b7912f643930' 
  AND token = 'nIGbdSGYZH8yLVAi/z4B1ZrBQSgnVMvPlUTZKLnsgPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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