SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ee1f9d3b4c544a76e3938ab5654c39f442aadca0a79975ae34ade530081c2ba' 
  AND token = 'JzzXydlMetwNbwzA32Mq1W5NSyARqZm4fctQWL1vUR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}