SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b09b55460b572885a26b0225af4e721d3071b675bd056861ef70e04bfa22ab8' 
  AND token = '1OXz8bqVkGmwI2Z8XQmxgf7OKYKJlentmntBmkoVV+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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