SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a2ba1d3be30a8c6745307506887c20e26cd3bdb45f9bee45acb35683ba32a6b' 
  AND token = 'psgfrFGqknFFtLT5GBhjrmclb20zSsB4jBORHXGDBHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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