SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b80ba574c592934fa0f3051409b34de92797cddceb7644d873ce7d5e10da69f' 
  AND token = 'aRB/yfyvSQAOCsKzugvD0TcXdKEpPBK2w8OyJmZLfVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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