SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0845278a51148d4ee271ffee4bb5386aeb779fbc96902f23e6eed286fc27f045' 
  AND token = 'z9H9PBxfwIHx0cte2nFVsTuxumMCWgJjNB4NMkPrWqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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